Folding square



No. 612,520. Patented out. la, |893..v

mw. JAmsoN. y

FOLDING SQUARE.

(Application filed Oct. 25, 1897.) N o M o d e l im y i UNITED STATES ATENT FFME FOLDING SQUARE.

SPECIFICATION forming` part of Letters Patent No. 612,520, dated October 18, 1898.` l

Application filed October 25,1897.

To all whom t may concern:

Be it known that I, ROBERT W. J AMIsON, a citizen of the United States, residingat Moore, in the county of Delaware and State of Pennsylvania, have invented a certain new and useful Improvement in Folding Squares, of which the following is a specification.

My invention relates to a new and useful improvement in folding squares, and has for its object to provide a simple and effective device of this description which will permit the short member to fold within the long member, thus facilitating the storage or transportation of this square; and a further object of my invention is to provide effective means for holding the two members rigidly at right angles to each other when open.

Vith these ends in View this invention consists in the details of construction and combination of elements hereinafter set forth and thenl speciiically designated by the claims.

In order that those skilled in the art to which this invention appertains may understand how to make and use the same, the construction and operation will now be described in detail, referring to the accompanying drawings, forming a part of this specification, in which- Figure l is a vieW of the square when adjusted-for use, one side of the long member being removed, so as to show the mechanism therein; Fig. 2, a view showing the square closed; Fig. 3, an enlarged View showing the members of the square after having been opened, but just prior to the locking of the same in this position; and Fig. 4, a similar view showing the short member of the square in the act of being swung closed. Y

In carrying out my invention as here embodied A represents the long member, which is preferably composed of three pieces, said pieces being the two sides and the filling B, which serves to hold these sides in their proper relative position, and these three sections are held together by the rivets C, and the short member D is pivoted at E between the sides of the long member, and the lling of the lastnamed member is suflicientl-y cut away to per-` mit the passing of the short member within the long member, as shown` in Fig. 2. The outer end of the filling is reduced, so as to form a spring F, and this spring terminates in the head Gr, adapted to fit within anotch formed in the heel of the short member, as shown in Figs. 1 and 3, and the result of this arrangement is that when the short member is swung closed this head rides upon the heel of the square and acts after the manner of a spring in a pocket-knife, and when the short member is closed this spring will hold itin such position against accidental displacement; but when it is necessary to open the short member sufficient outward force being exerted thereon will cause the heel of the blade to ride back the spring until said blade has assumed a right angle tothe handle, after which said spring willtend to hold the blade in this position.

It has been found in practice that a square thus constructed will not be rigidly held in the right-angle position by the action of the spring, there being a tendency from wear and other causes to bring about a certain amount of displacement, and to overcome this diftii culty I provide a toggle-joint consisting of the lever H, pivoted at I within the handle and at J to a short lever K, the latter being `pivoted at L to the blade, and this togglejoint is so proportioned and arranged that when the blade is in its right-angle position the two levers of the joint will not yet have been brought into alinement, as shown in Fig. 3, but by a certain amount of pressure being exerted upon the back of the toggle-joint it will be snapped into the position shown in Fig. 1, thus serving as a positive lock to hold the blade against displacement until the toggie-joint has been broken, as will be readily understood. The manipulation of the togglejoint is facilitated by a pin M, which projects through the slot N, and this is within access `of the user of the square and permits him to exert the necessary force `upon the togglejoint to bring its members into alinement, as just described. A suitable recess O is formed in the blade for the reception of the lever K,

and the notch P may be formed in the handle to facilitate the opening of the blade. A

square thus made will be as accurateas though blade and handle were made of one piece and yet will greatly facilitate the storing or `transportation of the same, since when not in use it may be folded within the dimensions of the handle.

IOO

ber to said ear, said toggle lying entirely between said plates in all positions, an arm secured to one of the members of said toggle and projecting through a curved slot formed in one of the plates, as and for the purpose set forth.

In testimony whereof I have hereunto afxed my signature in the presence of two subscribing witnesses.

ROBERT-W. JAMISON.

Witnesses:

S. S. WILLIAMSON, ALLIsoN W. MCCURDY. 

